Files with a naming convention like
.nfsXXXX are created by NFS clients when a file that is currently opened on a client is deleted by that client. The client renames the file to
.nfsXXXX which discourages other clients/processes from utilizing the file. The client that does the rename should delete the file once it's been closed by the client process. This delete might not occur if the client is dsiconnected, rebooted, or the process that would issue the delete is terminated.
These files are not generated by an ONTAP process and are only created in response to client requests.
Finding the NFS client and process using a
.nfsxxxx file may be very time consuming. It would require checking every process on every NFS client that could be accessing the NFS share containing the file. A utility such as
lsof may be used to determine the process using the
.nfsxxxx file. To prevent
.nfsXXXX files from being created, do not remove a file when it is open. If the
.nfsxxxx file is determined to no longer be in use then it may be removed. If a remove results in a new
.nfsxxxx file then a process on that NFS client has the file open.
Demonstration for creating and removing
- From the NFS client, create a file in the mounted NFS share and open it with the tail command. Suspend the process with
ctrl-zor open a new terminal to complete the rest of the demonstration.
shell# echo test > foo
shell# tail -f foo
+ Stopped tail -f foo
- Remove the file
footo make the NFS client create the
shell# rm foo
shell# ls -A
- Observe that subsequent
rmcommands only make the NFS client rename the file again.
shell# rm .nfs5ACF
shell# ls -A
- Locate the process that has the file open using lsof or fuser.
shell# lsof ./.nfs6ACF
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
tail 25725 root 3r REG 8,1 27603 6647 .nfs6ACF
shell# fuser .nfs6ACF
- Finally, terminate the process holding the file open and observe that the
.nfsxxxfile is now removed.
shell# kill 25725
shell# ls -al
drwxr-sr-x 2 root src 400 Mar 29 15:39 .
drwxrwsr-x 36 root src 3336 Mar 21 09:37 ..
Whether it can be determined from ONTAP if a client has the file open depends on the protocol used:
- NFSv3: Usually no lock is present as NFSv3 is stateless.
- NFSv4.0 or 4.1: If a client has the file open, an
nfsv4.1lock will be present.
cluster2::> vserver locks show -vserver svm1 -volume unix -path /unix/.nfs000000000000006000000009
Volume Object Path LIF Protocol Lock Type Client
-------- ------------------------- ----------- --------- ----------- ----------
nfsv4 share-level 10.64.24.10
Sharelock Mode: write-deny_none
- Only if an nfsv4 or nfsv4.1 lock is present for a file can the client IP be determined.
- If no locks are present, there are no commands that can show if an NFSv3 client is using the file.
NOTE: For ONTAP releases prior to 9.8, obtaining the client IP for nfsv4 and nfsv4.1 type locks requires additional diag mode commands.